Evaluation of elite lettuce strains resistant to the main breeds of Bremia lactucae found in the state of São Paulo

• Grant number: 20/16616-4
• Support Opportunities: Scholarships in Brazil - Scientific Initiation
• Start date: May 01, 2021
• End date: December 31, 2021
• Field of knowledge: Agronomical Sciences - Agronomy - Crop Science
• Principal Investigator: Pablo Forlan Vargas
• Grantee: José Augusto Canales Barbieri
• Host Institution: Faculdade de Ciências Agrárias. Universidade Estadual Paulista (UNESP). Campus do Vale do Ribeira. Registro , SP, Brazil

Abstract

Lettuce (Lactuca sativa L.) is one of the most important vegetables in Brazil and in the world, in 2017 it was the 18th most marketed commodity at Ceagesp. Among the phytosanitary threats that can occur on lettuce, the Mildew stands out, having the fungus Bremia lactucae as its causal agent that can cause great damages to the producers mainly in winter times, where the environmental conditions are propitious to mildew. The main method of disease control is the use of chemicals registered within the Ministry of Agriculture, Livestock and Supply (MAPA) for lettuce culture, however, this technique is not fully efficient in mildew control and, in addition, there exists the possibility of environmental contamination. An alternative to this problem is the development of lettuce cultivars resistant to the pathogen, a measure little explored by programs conducted by the private sector in Brazil, and this is a study that must be continuous, since that new breeds Bremia lactucae can arise. Thus, in view of the above, the objective of this study is to agronomically evaluate elite strains of lettuce resistant to the main breeds of Bremia lactucae identified in the state of São Paulo. The experiment will be installed in an area on the premises of Universidade Estadual Paulista - Campus Experimental de Registro. Four experiments will be carried out, being implemented in the first week of May, June, July and August. The experimental design will be in randomized blocks with three replications, with treatments consisting of eight lines of lettuce, and two commercial cultivars, Solaris (Seminis®) and Valentina (Sakata®). Developmental characteristics of plants and production components will be evaluated. The data will be subjected to analysis of variance using the F test, and the means compared by the Tukey test at 5% probability, for each of the planting seasons. Subsequently, a joint analysis of the experiments will be carried out to identify possible interactions between the studied genotypes and times of establishment. (AU)